Ignition contact set



Aug. 22, 1961 F. s. KERR 2,997,553

IGNITION CONTACT SET Filed Dec. 50, 1958 v l I I INVENTOR.

United States Patent 2,997,553 IGNITION CONTACT SET Fred S. Kerr, Royal Oak, Miclr., assignor to Holley Carburetor Company, Van Dyke, Mich., a corporation of Michigan Filed Dec. 30, 1958, Ser. No. 783,982 8 Claims. (Cl. 20030) The present invention relates to an ignition contact set.

It is an object of the present invention to provide an improved ignition contact set characterized by the economy of production, simplicity of construction, and improvement in operation.

It is a feature of the present invention to provide an ignition contact set comprising a contact bracket having a pivot post thereon, a rubber bushing surrounding the post, and a breaker arm assembly comprising a nonmetallic arm portion having an integral rubbing block at one end and terminating at its other end in a substantially semi-cylindrical portion shaped to surround approximately one-half of the rubber bushing, a spring having one end fixedly secured to said arm portion and having a substantially arcuately bent portion engaging the side of the bushing opposite the semi-cylindrical end portion of said arm portion.

It is a further feature of the present invention to provide a construction as described in the preceding paragraph which includes a breaker arm formed of relatively light metal having an end portion engaging a side of the non-metallic arm portion and connected thereto by rivets which extend through the non-metallic arm portion and also through a portion of said spring to provide electrical connection between the spring and breaker arm frame.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a side elevation of the ignition contact set with parts broken away.

FIGURE 2 is a plan view of the breaker arm set.

As best seen in the drawings, the breaker arm set comprises a contact bracket indicated generally at 10 having a fiat base or mounting portion 12 provided with elongated mounting openings 14 and 16 at opposite ends thereof. An elongated intermediate portion of the bracket is struck out of the base portion thereof leaving an opening as indicated at 18, the struck out portion being bent to extend upwardly to provide a pivot post 20. A relatively smallcyliudrical button 22 is extruded downwardly from the base portion 12 of the bracket and provides a locating button which is received in a locating opening 24 in a plate 26 on which the contact bracket is mounted. Inasmuch as the bracket is somewhat weakened by the portion struck out to provide the post 20, an edge portion thereof is turned upwardly to provide a stiffening rib 28 and a portion of the stifiening rib extends upwardly to provide a mounting post 30. Another portion of the bracket is bent to extend upwardly to form a contact post 32 to which a contact 34 is secured.

Surrounding the pivot post 20 is a rubber sleeve or bushing 36 which is non-rotatably secured on the post due to the rectangular cross-section thereof, as best seen in FIGURE 2.

The breaker arm assembly comprises a molded fiber arm portion 38 having one end formed to extend laterally to provide a rubbing block 40 and having its other end 'formed in the shape of a semi-cylinder as indicated at 42,

and dimensioned to embrace the outer surface of the rubber bushing 36 through approximately one-half of its circumferential extent. The molded fiber arm portion 38 is mounted on the rubber bushing by means including a leaf spring 44 one end of which is connected to the mount ing post 30 by a bolt 46, nut 48, conducting washers 50 and 52, and an insulating sheet 54 extending over the post 30. It will be understood that the mounting post 30 includes a relatively enlarged opening and that by the previously described arrangement of parts, the spring is an electrical contact with the bolt 46 and metallic parts associated therewith but is suitably insulated from the mounting post 30.

The opposite end of the spring 44 has a portion 56 shaped into partially cylindrical configuration and adapted to engage the side of the rubber bushing 36 opposite to the portion thereof engaged by the semi-cylindrical end 42 of the molded fiber arm portion 38.

Also connected to the molded fiber arm portion 38 is a metallic breaker arm frame 60 formed of light gauge metal bent to provide a stitfening rib 61 and terminating at one end portion in a contact 62 movable into and out of engagement with the contact 34 to make and break a circuit as is well understood in the art. The body portion of the breaker arm frame has edge portions 63 bent up to form a shallow channel in which an intermediate portion of the molded fiber breaker arm portion is received. The parts are assembled together by rivets 64 which extend through a straight end portion 66 of the spring 44, through openings in the molded fiber breaker arrn portion, and through openings provided in the body of the breaker arm frame. The rivets not only provide a rigid assembly of breaker arm components but also serve to establish efficient electrical contact between the spring and breaker arm frame.

The provision of the rubber bushing surrounding the pivot post provides a mounting for the breaker arm assembly which permits the breaker arm assembly to move about the axis of the pivot post without the necessity of providing specific bearing portions. The rubber bushing acts in torsion and hence cylindrical bearing surfaces are not required.

Since the rubber bushing acts in torsion a second very important advantage is obtained by its use. Torsion of the rubber bushing tends to absorb energy as the breaker arm moves and hence acts as a dampening effect which substantially eliminates contact bounce during operation.

The present construction is extremely economical. The contract bracket is formed by a stamping operation from sheet metal and the same operation provides the pivot post. The pivot post need not be machined to cylindrical configuration nor provided with cylindrical bushings or bearings. Instead, it is provided with a rubber bushing subjected in use to torsion which has its outer surfaces engaged between a semi-cylindrical end portion of the breaker arm and a similarly shaped portion of the leaf spring which biases the breaker arm in a direction to cause engagement between its contact point and a fixed contact point carried on the contact bracket. v

The breaker arm assembly is strong, rigid, yet relatively light and in its assembly from component parts is arranged to have the necessary electrical conductivity from its contact point to the biasing spring connected thereto.

The drawing and the foregoing specification constitute a description of the improved ignition contact set in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post and a laterally extending projection thereon forming a rubbing post, a metallic arm portion fixedto said non-metallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion.

2. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post and a laterally extending projection at one end thereof forming a rubbing post, a metallic arm portion fixed to said non-metallic arm portion having a movble breaker contact movable into and out of engagement with said fixed contact, and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion.

3. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, said post assembly comprising a post element and a generally cylindrical nonrotatable bushing thereon, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post and a laterally extending projection thereon forming a rubbing post, a metallic arm portion fixed to said non-metallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly'opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion.

4. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, said post assembly comprising a post element and a generally cylindrical torsion bushing thereon, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post and a laterally extending projection thereon forn1- ing a rubbing post, a metallic arm portion fixed to said non-metallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post as sembly opposite the side thereof engaged by the part1) cylindrical end of said non-metallic breaker arm portion.

5. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post and a laterally extending projection thereon forming a rubbing post, a metallic arm portion fixed to said non-metallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion, said metallic arm portion and said leaf spring being assembled against opposite sides of the non-metallic portion of said breaker arm, and electrically conducting rivets extending through overlapped portions of said spring, metallic and non-metallic breaker arm portions to electrically connect said spring and metallic arm portion.

6. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, said post assembly comprising a post element of noncircular cross section and a generally cylindrical torsion bushing having an opening therein of substantially the same cross section as said post element for tightly receiving said post element, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elon gated non-metallic portion having a partly cylindrical end engaging and partly surrounding said pivot post assembly and a laterally extending projection thereon forming a rubbing post, a metallic arm portion fixed to said nonmetallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion.

7. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, said pivot post assembly comprising a post element of non-circular cross section and a generally cylindrical torsion bushing having an opening of substantially the same cross section as said post element for tightly receiving said post element, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated non-metallic portion having a partly cylindrical end engaging and partly surrounding said torsion bushing and a laterally extending projection thereon forming a rubbing post, a metallic arm portion fixed to said non-metallic arm portion having a movable breaker contact movable into and out of engagement with said fixed contact, a leaf spring connected to said breaker arm and'to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate position engaged against the side of said pivot post assembly opposite the side-thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion, said metallic arm portion and said leaf spring being assembled against opposite sides of the non-metallic portion of said breaker arm, and electrically conducting rivets extending through an overlap portion of said spring, metallic and nonmetallic breaker arm portions to electrically connect said spring and metallic arm portion.

8. An ignition contact set comprising a support bracket having a pivot post assembly and a contact post thereon, said pivot post assembly comprising a post element of non-circular cross section and a generally cylindrical torsion bushing having an opening of substantially the same cross section as said post element for tightly receiving said post element, a fixed breaker contact on said contact post, a breaker arm pivotally mounted on said pivot post, said breaker arm comprising an elongated nonmetallic portion having a partly cylindrical end engaging and partly surrounding said torsion bushing and a laterally extending projection at one end thereof forming a rubbing post, a metallic arm portion fixed to said nonmetallic arm portion having a movable breaker contact movable into and out of engagement with said fixed ontact and a leaf spring connected to said breaker arm and to said bracket to bias said breaker arm toward said contact post, said spring having an intermediate portion engaged against the side of said pivot post assembly opposite the side thereof engaged by the partly cylindrical end of said non-metallic breaker arm portion, said metallic arm portion and said leaf spring being assembled against opposite sides of the non-metallic portion of said breaker arm.

References Cited in the file of this patent UNITED STATES PATENTS Thomas July 14, Watson Sept. 28, Person Nov. 29, Terry Dec. 25, Mallory Dec. 7, Harrington et a]. July 21, 

